U.S. patent application number 11/197277 was filed with the patent office on 2007-02-08 for led light.
Invention is credited to David Gendreau, Stephen B. Offiler, Marcus Poisson.
Application Number | 20070030672 11/197277 |
Document ID | / |
Family ID | 37717450 |
Filed Date | 2007-02-08 |
United States Patent
Application |
20070030672 |
Kind Code |
A1 |
Offiler; Stephen B. ; et
al. |
February 8, 2007 |
Led light
Abstract
The lamp head of an LED utility light provides LED elements, a
housing, a power source, and optical means produces from the LED
element output a substantially clean and uniform light beam over at
least 24-32 inches from the lamp head. In another embodiment, a
flexible stalk is connected at one end to the housing and at the
other to the lamp head. Yet another embodiment shows a LED module,
secondary optics and a heat sink; a renewable power source, a
flexible neck linked at one end to the housing and at the other
supporting a lamp head housing an LED elements array. Optical means
produces a substantially uniform light beam from the LED element to
a distance of at least 5 feet from the lamp head, the flexible neck
having quick-release capacity to allow alternation between white
LED die and blue ultraviolet LED die.
Inventors: |
Offiler; Stephen B.;
(Sterling, CT) ; Gendreau; David; (Cranston,
RI) ; Poisson; Marcus; (Pawtucket, RI) |
Correspondence
Address: |
LACKENBACH SIEGEL, LLP
LACKENBACH SIEGEL BUILDING
1 CHASE ROAD
SCARSDALE
NY
10583
US
|
Family ID: |
37717450 |
Appl. No.: |
11/197277 |
Filed: |
August 4, 2005 |
Current U.S.
Class: |
362/198 ;
362/199; 362/396 |
Current CPC
Class: |
F21V 29/83 20150115;
F21Y 2115/10 20160801; F21V 21/0832 20130101; F21V 21/088 20130101;
F21V 21/096 20130101; F21L 4/04 20130101; F21V 21/32 20130101 |
Class at
Publication: |
362/198 ;
362/199; 362/396 |
International
Class: |
F21L 4/04 20060101
F21L004/04 |
Claims
1. An LED work or utility light comprising: a lamp head, which
houses an array of LED elements; a housing; a power source; and an
optical means that takes the output of said LED elements and
produces a substantially clean and uniform beam of light over a
range extended from said lamp head to a distance of at least 24 to
32 inches.
2. The LED work or utility light of claim 1, wherein said optical
means further comprises a lens and a reflector.
3. The LED work or utility light of claim 1, further comprising a
heat sink.
4. An LED utility light comprising: a lamp head, which houses an
array of LED elements; a housing; a power source; a flexible stalk
that is connected at a first end to said housing and at a second
end to said lamp head; and an optical means that takes the output
of said LED elements and produces a substantially clean and uniform
beam of light over a range extended from said lamp head to a
distance of at least 24 to 32 inches.
5. The utility light of claim 4, wherein said optical means further
comprises a lens and a reflector.
6. The utility light of claim 4, further comprising a heat
sink.
7. The utility light of claim 4, wherein said power source is a
power adapter.
8. The utility light of claim 4, wherein said power source is a
battery.
9. The utility light of claim 4, wherein said housing further
comprises means for removably securing said utility light to a
physical element or to component within a work space.
10. The utility light of claim 4, wherein said means for removably
securing is at least one magnet that is disposed on at least one
surface of said housing.
11. The utility light of claim 4, wherein said means for removably
securing is at least one clamp.
12. The utility light of claim 4, wherein said utility light can be
secured to an element in a workspace and wherein a substantially
uniform light can be generated in said workspace.
13. The utility light of claim 4, wherein said LED elements emit
light which can be focused and directed by adjusting at least a
first a lens and a first reflector through said optical means.
14. The utility light of claim 4, wherein said LED elements provide
a light having an angle of dispersion between about 35 to about 45
degrees.
15. The utility light of claim 4, wherein said flexible neck has a
quick-release means for allowing removal of said flexible neck from
said housing.
16. An LED utility light comprising: a housing having a LED module,
secondary optics, and at least one heat sink; a renewable power
source; a flexible neck that is connected at a first end to said
housing and at a second end supports a lamp head that houses an
array of LED elements; and an optical means that takes the output
of said LED elements and produces a substantially uniform beam of
light over a range extended from said lamp head to a distance of at
least five feet, wherein said flexible neck has a quick-release
means for allowing alteration between a lamp head housing white LED
die and a lamp head housing blue ultraviolet LED die.
17. The utility light of claim 8, wherein said battery is a
disposable replaceable cell.
18. The utility light of claim 8, wherein said battery is a
rechargeable cell.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a light-emitting diode
(LED) light assembly. More particularly, the present invention
relates to a readily positionable LED light assembly that is
adapted to provide a substantially clean and uniform beam of
light.
[0003] 2. Description of the Prior Art
[0004] Portable lighting devices of the type frequently known as
shop, work, utility or task lights, and other portable lighting
devices have limitations in that they often fail to provide a clean
light beam. Often, the emitted light has bright or shady spots.
These obstructions to the light beam may be caused by the
interference of a filament with the emitted light beam. A clean and
uniform beam of light is necessary to provide a bright beam over a
distance.
[0005] Work lights also require a clean and bright beam of light.
One of the essential requirements for work in a close or confined
work space is adequate lighting. Non-limiting examples of a
confined work space include the engine compartment, the space below
the dashboard, or the chassis of an automobile.
[0006] General lighting such as fluorescent overhead lighting
typically available in a workspace, such as in a garage, is
insufficient for close work. The shadows cast by the many
components of an object of work make working without directed
illumination nearly impossible.
[0007] A typical lighting solution has been the conventional shop
light which includes an incandescent or fluorescent light bulb
surrounded on one side by a protective cage and on the other side
by a reflective plate. A hook is usually provided for hanging the
light from an overhead support. The hook is either a fixed device
or a swivel device attached to the reflective plate or the
protective cage. The shop light hangs by the hook and is oriented
by a worker to direct the light as needed. One limitation of the
shop light is finding a suitable location for hanging. Also, when
suspended by a swivel hook, the light frequently rotates or moves.
The light output direction shifts, thereby reducing its
usefulness.
[0008] Shop lights are adequate for general work, but do not
provide adequate light for working in close or confined work areas.
Moreover, these types of lights are usually too large and
cumbersome to fit into constricted workspaces. As a result, light
cannot be directed into the desired locations due either to
obstructions or the physical size of the components. Also, many of
the existing work or utility lights reach uncomfortably high
temperatures over an extended use period and these can become
hazardous to the user when used in a close work space.
[0009] Additionally, shop lights emit diluted or less intense light
in a broad area, rather than concentrating light on a particular
desired location. The further a light is positioned away from the
work space, the more diluted the light intensity. Thus, shop lights
often emit an "overspray" of light. This "overspray" is very
distracting and can cause eye irritation. The eye irritation can
also lead to time consuming and dangerous working conditions.
[0010] Light-emitting diodes (LEDs) are a commonly used light
source in applications including lighting, signaling, signage, and
displays. LEDs have several advantages over incandescent and
fluorescent lamps, including high reliability, long lifetime, and
high efficiency.
[0011] U.S. Pat. No. 6,231,207 to Kennedy et al. discloses a light
emitting diode flashlight lamp. This reference discloses the use of
an LED as a direct source of light for a flashlight assembly. As
shown, the LED is contained in an end cap housing that is threaded
onto an end of a translucent cylinder. In this manner, the end cap,
and corresponding LED can be positioned to shine light away from
the cylindrical tube (i.e., in flashlight mode) or can be
positioned to shine light into the cylindrical tube (i.e., in lamp
mode). Even with the bright white light LEDs currently available,
the LED light source fails to provide a light source having optic
tolerances that provide a sufficiently clean, broad and intense
light.
[0012] A need therefore exists for a readily positionable compact
LED light assembly that is adapted to provide a clean, broad and
uniform light whether over a distance or in a confined
workplace.
SUMMARY OF THE INVENTION
[0013] It an object of the present invention to provide a portable
light that is free of filament shading or bright spots.
[0014] It is another object of the present invention to provide a
light that utilizes one or more LEDs as the light source.
[0015] It is also an object of the present invention to provide a
light having LED optics spatially arranged such that the light
tolerances provide a clean and bright light.
[0016] It is another object of the present invention to provide an
LED work or utility light that provides a substantially uniform and
bright light over distances encountered by workers, such as
automobile mechanics, under typical working conditions.
[0017] It is a further object of the present invention to provide
an LED utility or work light that provides a substantially clean,
uniform and bright light in a confined workspace.
[0018] It is yet another object of the present invention to provide
an LED utility light having an optical means that is positioned on
a flexible neck.
[0019] It is still another object of the present invention to
provide an LED utility light that provides a lighted area
approximately twenty inches in diameter at a distance of
approximately 24 to 32 inches.
[0020] It is still a further object of the present invention to
provide an LED utility light wherein the angle of dispersion of the
LED light beam is approximately between 35 degrees and 45
degrees.
[0021] It is a yet further object of the present invention to
provide an LED utility light having means for securing the utility
light housing to a surface within a work space.
[0022] These and other objects and advantages of the present
invention are achieved by an LED work or utility light comprising a
lamp head, which houses an array of LED elements, and an optical
means, as well as a housing and a power source, that generates the
output of the LED elements and produces a substantially clean and
uniform beam of light over a range extended from the lamp head to a
distance of at least 24 to 32 inches.
[0023] The objects and advantages of the present invention are also
achieved by an LED utility light comprising a lamp head, which
houses an array of LED elements, a housing, a power source, a
flexible neck that is connected at a first end to said housing and
at a second end to said lamp head, and an optical means that takes
the output of the LED elements and produces a substantially clean
and uniform beam of light over a range extended from said lamp head
to a distance of at least five feet.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The foregoing and still other objects and advantages of the
present invention will be more apparent from the following detailed
explanation of the preferred embodiments of the invention in
connection with the accompanying drawings.
[0025] FIG. 1 is a block diagram of the LED light of the present
invention;
[0026] FIG. 2 is an exploded perspective view of the lamp head of
the LED light of the present invention;
[0027] FIG. 3 is a cross-sectional view of the lamp head of the LED
light of the present invention;
[0028] FIG. 4 is a perspective view of an LED utility light
according to one embodiment of the present invention, illustrating
the lamp head and flexible neck or stalk in a storage position;
[0029] FIG. 5 is a perspective view of the LED utility light of the
present invention, illustrating the lamp head and flexible stalk in
an extended position;
[0030] FIG. 6 is an environmental view illustrating the LED utility
light of the present invention being employed within an automobile
engine compartment to illuminate an automobile engine; and
[0031] FIG. 7 is an exploded side perspective view of the LED
utility light of the present invention, illustrating the magnetic
means for attachment to a ferromagnetic surface within a
workspace.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] Referring to the drawings and, in particular, FIG. 1 there
is illustrated an LED light according to the present invention
generally represented by reference numeral 10. LED light 10
preferably has a lamp head 20 and a housing 25. Housing 25 contains
a power routing element 115, a rechargeable battery 35, recharge
circuitry 40, and LED (light emitting diode) driver circuitry
50.
[0033] As shown in FIGS. 2 and 3, lamp head 20 houses an LED module
50, an optic assembly 55 comprising a lens 60 and a reflector 65, a
power lead 70, and a heat sink 75. LED module 50 is preferably a
packaged array of a multiplicity of individual LED semiconductor
chips disposed on a substrate. The substrate is preferably
engineered for optimizing thermal performance and heat transfer,
such as substrates supplied by Lamina Ceramics of Westampton, N.J.
LED module 50 preferably incorporates means for electrostatic
discharge protection.
[0034] LED light 10 employs an LED optical system of the type
disclosed in U.S. Published Application Number 2004/0264004 A1 to
Jacobson et al., incorporated herein by reference. The '004
Publication is directed to a non-imaging optical system for
processing first and second light distributions. The non-imaging
optical system includes at least two refractive surfaces, at least
one reflective surface nearer to the first light distribution along
at least one ray path than the nearer of the two refracting
surfaces and the reflective surface. The refractive surfaces
cooperate to redirect light edge rays of the first light
distribution into the neighborhood of the edge of the second light
distribution with a single reflection from the reflecting
surface.
[0035] More specifically, the disclosed optical system uses an
aspheric dielectric lens with two refraction surfaces at the large
aperture of a hollow, funnel-shaped reflector. The back surface of
the dielectric (the surface facing the reflector) has a higher
curvature than the front surface, making the structure more
compact. This approach achieves performance comparable to a
non-truncated CPC, with much better compactness. Aspect ratios
range from 0.4 to 0.7. Moreover, the dielectric lens has acceptably
low thickness for cost-effective molding. Unlike the earlier
designs, the small aperture of the funnel is advantageously
positioned behind the optic, so that a source or detector can be
supported by a much larger circuit board or heat sink without
shadowing.
[0036] LED emitted light provides a collimated beam having a wide
angle of dispersion. LED module 50 and optic assembly 55 provide a
substantially uniform beam of light having little diffusion. In a
preferred embodiment, LED module 50 and optic assembly 55 provide
an illuminated area approximately 18 to 20 inches. Actual
prototypes and production components have measured about 19 inches
in diameter when the LED light 10 is at a distance of two feet from
an object to be illuminated. Preferably, the angle of dispersion of
the light beam of LED light 10 is between about 35 to about 45
degrees. The LED light beam provides a uniform and bright light at
these angles, thereby enabling illumination within a confined work
space. FIG. 6 illustrates illumination of an automobile engine work
space W by LED light 10.
[0037] Optic assembly 55, comprising lens 60 and reflector 65, is
dedicated to LED module 50. The spatial relationship between lens
60 and reflector 65 provides the tolerances necessary to providing
a clean beam of light. Optic assembly 55 gathers the uncontrolled
light emitted from LED module 50 and directs such light into an
output pattern with a relatively constant intensity. Optic assembly
55 produces a substantially uniform beam of light from the output
of LED module 50 over a range extended from lamp head 20 to a
distance of at least 24 to 32 inches, although the optic assembly
55 produces a substantially uniform beam of light. This uniformity
extends to distances of 40 to 50 feet and sometimes more. However,
the brightness of an illuminated area will clearly also be a
function of the distance from the optic assembly and a function of
ambient light conditions.
[0038] The output pattern is preferably cone-shaped and provides
relatively constant intensity across a plane normal to the axis of
the cone. LED module 50 preferably also has at least one heat sink
75 for dispersing the heat generated by LED module 50. Heat sink 75
is preferably a machined unit.
[0039] To obtain a clean or uniform beam of light, the optic
assembly 55 should be held dimensionally in the correct position
relative to LED array 50. In the disclosed design, the position of
LED array 50, and the position of optic assembly 55, are controlled
by the heat sink, which is a machined unit having reasonably good
tolerances. Required tolerances are no tighter than those produced
routinely and typically by computer-numerically-controlled
machining equipment.
[0040] Heat sink 75 is preferably a conical structure and functions
to draw heat away from the LED module and transfer it to the
ambient air. Heat sink 75 preferably has a series of corrugated
protrusions or ribs 107 as shown. Ribs 107 optimize surface area
for dissipation of heat. Heat sink 75 is engineered from a suitable
electrically and thermally conductive material. A non-limiting
example of a thermally conductive material is aluminum. Heat sink
75 also serves to conduct electrical power to LED module 50.
Structurally, heat sink 75 further provides the required precise
dimensional location of LED module 50 and reflector 65 and support
for LED module 50.
[0041] Lamp head 20 may optionally have a cage 85, a retaining ring
90, a connecting means 95 for mechanical and electrical connection
of the heat sink to LED module 50. Cage 85 protects heat sink 75
from casual contact with heat sensitive materials, such as human
skin. Cage 85 also functions to support bushing 100 and to provide
an engageable connection with retaining ring 90. Cage 85 is formed
of an electrically insulating material such as plastic.
[0042] Retaining ring 90 functions to retain the lamp head 20 while
providing uniform pressure on optic assembly 55, thus holding
reflector 65 and lens 60 in precise coaxial alignment relative to
one another. Retaining ring 90 additionally provides protection
from mechanical shock and impact as well as a measure of moisture
resistance. Retaining ring 90 further provides a simple, tool-free
means for field disassembly, enabling replacement of a compromised
lens. Retaining ring 90 is preferably formed of an elastic
material.
[0043] The bushing 100 is formed of an electrically conductive
material such as brass. Bushing 100 is installed in cage 85,
serving as both a mechanical mounting means as well as an
electrical conductor of a polarity opposite to that of the heat
sink 75. The bushing 100 may be press fit, threaded or connected by
any other known means.
[0044] Connecting means 95 may be any means known in the art for
providing mechanical and electrical connection. Connecting means 95
is preferably a screw and washer assembly.
[0045] As illustrated in FIGS. 4 and 5, lamp head 20 is coupled to
housing 25 by a flexible stalk or neck 105. Flexible stalk 105 is
preferably flexible along its entire length and is preferably
permanently attached to housing 25. It should be noted that
flexible stalk 105 may be flexible in one or a plurality of
locations along its length. The lamp head 20 is pivotally mounted
to flexible stalk 105 such that the lamp head 20 is positionable
along at least two axes.
[0046] FIG. 4 illustrates lamp head 20 and flexible stalk 105 in a
closed or storage position. When lamp head 20 is in the storage
position it may be secured to housing 25 by a hook means 110. Hook
means 110 may be any fastening means known in the art. While the
hook 110 secures the lamp head 20 in one position (as shown in FIG.
4), it is preferably movable and positionable such that it may
support the housing 25 in a plurality of positions. Thus, with hook
110 deployed as shown in FIG. 5, by virtue of a detented
ball-and-socket joint 111, the housing 25 can be hung from a
support in a plurality of positions or orientations.
[0047] Hook means 110 is preferably coupled to housing 25 by a ball
and socket-type mechanism. Hook means 110 also functions to provide
a means by which to hang LED light 10 from a support. FIG. 5
illustrates lamp head 20 and flexible stalk 105 in at least a
partially extended position.
[0048] Housing 25 preferably has an external power port (not
shown). External or input power may be directed to recharge
rechargeable battery 35 via the external power port. External power
may alternately be directed to drive LED driver circuitry 45 when
rechargeable battery 35 is depleted.
[0049] Referring again to FIG. 1, input power may be supplied to
recharge circuitry 40 by an automobile battery 16 or a plug-in
transformer module commonly known as wall wart or power adapter 17.
Input voltage is preferably about 11.5 to about 18 VDC. It should
be noted that input power supplied by wall wart 17 may have some
ripple effect. Accordingly, recharge circuitry 40 is preferably
designed to be immune from such effect. A "smart charger" may be
used, which is capable of detecting the state of the battery, and
it is self-regulating to optimize recharge. A smart charger
provides the most appropriate voltage and current characteristic to
a selected battery type, such as a NiMH battery pack, of recharge
circuitry 40, and additionally prevents overcharging.
[0050] The external power port is adapted to accept 12 VDC from an
automotive battery via a cigarette lighter outlet or directly from
the battery via "alligator"-type clips. A partially depleted
automobile battery has a terminal voltage of approximately 11.5
VDC. A normally running automobile has a system voltage of
approximately 14.5 VDC. However, it should be noted that transients
common to the automotive electrical system, which boost system
voltage to approximately 18 VDC may exist.
[0051] The external power port may also be adapted to accept 12 VDC
from wall wart 17. The North American standard for input voltage is
120 VAC 60 Hz. Nominal output voltage will be 12 VDC at rated
current.
[0052] Input power to LED driver circuitry 45 is approximately 8.4
VDC to 18 VDC. Input power will contain some ripple if the power
source is a wall wart. Accordingly, LED driver circuitry 45 is
preferably designed to be immune to such ripple.
[0053] Power routing element 115 enables a user to switch between
several modes of operation. A first mode draws internal power from
rechargeable battery 35 for normal LED operation. A second mode
draws external power to LED module 50 if lighting is desired. A
third mode draws external power to the battery recharge circuit, if
LED module 50 is not operational. Power routing element 115 may be
any mechanical means for switching known in the art such as switch
contacts. Power routing element 115 may be solid-state means or any
combination of mechanical and solid-state means.
[0054] In a preferred embodiment, LED light 10 further has a charge
status indicator (not shown). The charge status indicator may be
any indicator known in the art such as a small lamp, an audio
device or any other signaling means.
[0055] Other embodiments are possible that use primary cells
(replaceable, non-rechargeable batteries). In these embodiments,
the energy source is exclusively the primary cells; there is no
external port nor is there any need for power-routing 115 nor for
recharge unit 40.
[0056] The lamp head 20 is interchangeable between a white light
mode and any other commercially available LED color. Non-limited
examples include ultra-violet, violet, blue, green, amber, and red.
Since there is no such thing as a white LED die, a close
approximation of white is commercially obtained by coating blue LED
die with various phosphors.
[0057] Various lighting applications may benefit from illumination
via a colored light other than white. One example includes
detection of ultraviolet dyes employed in leak detection and
security; another includes red light, which is sometimes employed
in low-light conditions to preserve night vision.
[0058] The LED module 50 preferably consists of a cell array
populated with a prescribed number of LED die. In a preferred
embodiment, LED module 50 consists of a Lamina 7-cell array
populated with 42 LED die. In a more preferred embodiment, the LED
die are wired in a configuration having three in a series and
fourteen sets in parallel. Nominal forward voltage of a single die
is approximately 3.5 VDC. Accordingly, three LED die in a series
provide approximately 10.5 VDC. Nominal forward current is 30 mA
per series of die. Accordingly, fourteen sets in parallel provide a
forward current of 420 mA.
[0059] To provide the brightest light for illumination, however any
color LED die may be employed. In an alternate embodiment, LED
module 50 has blue ultraviolet LED die. Blue ultraviolet LED may be
useful for automotive leak detection as well as for non-automotive
uses such as security, adhesive curing, detecting Freon leaks in
refrigeration systems and any other known use. In this embodiment,
LED module 50 preferably has a Lamina 7-cell array populated with
fourteen blue die in the range of 470 nm. In a more preferred
embodiment, fourteen blue die are wired in parallel and run at
approximately 420 mA at approximately 3.5 VDC. LED module 50 may
alternately have twenty-eight blue die in the range of 470 nm. In
this embodiment, twenty-eight die are wired in two parallel lines,
fourteen in a series, and run at 420 mA at approximately 7 VDC.
[0060] Flexible stalk 105 preferably has a quick-release means
incorporated therein for allowing rapid removal of the lamp head 20
and changeover from a white lamp head to a UV or any other LED lamp
head. The quick-release means preferably has a mechanical mounting
system and a set of electrical contacts.
[0061] As shown in FIG. 5, housing 25 preferably has a series of
attaching means 120 disposed along at least one outer surface of
housing 25. Attaching means 120 may be magnets, Velcro, clamp or
other suitable attachment means. Attaching means 120 enable housing
25 to be attached to any suitable working surface such as an
automobile engine. Alternately, LED light 10 may have clamp or
other suitable means for fastening housing 25 to a work space.
[0062] The present invention has been described with particular
reference to the preferred embodiments. It should be understood
that the foregoing descriptions and examples are only illustrative
of the present invention. Various alternatives and modifications
thereof can be devised by those skilled in the art without
departing from the spirit and scope of the present invention.
Accordingly, the present invention is intended to embrace all such
alternatives, modifications, and variations that fall within the
scope of the appended claims.
* * * * *